Membrane plastic electrolytic cell of the bipolar type

ABSTRACT

Improvements to a membrane electrolytic cell of the bipolar type, are based on the configuration of its structure, allowing it to have an independent distribution of brine feeds, since it is possible to visually inspect the flow continuity through the two translucent restrictive hoses. The hoses connect to two upper compartments, wherein the compartments ensure the anodic and cathodic containers collects product discharges and separates the turbulence area from the membrane area. This allows spill through to the translucent annular hose to act as a sight glass. This improvement refers also to a reinforced structure with a bulge, to keep the dividing integral injected plastic plate seal sides of the anode and cathode plastic frame compartments perpendicular to keep the minimal gap between electrodes, required to achieve a lesser voltage drop in the electrolytic cell, involving greater current efficiency and electric power (kWh) savings.

OBJECT OF THE INVENTION

The object of this invention refers mainly to structural improvements to a plastic electrolytic cell, allowing it to have greater functionality and operation efficiency of electrolysis to obtain chlorine, alkalis and a variety of products by means of an activated titanium electrode and a steel cathode or activated nickel cathode or other metals suitable for the process and conventional ionic exchange membranes as well as other uses in electrodialysis processes and electro-oxidation of chemical solutions.

BACKGROUND

To this date, there are different types of electrolytic cells, such as the one depicted in Mexican patent number PA/A/2003/008797, titled ANODE STRUCTURE FOR MERCURY CATHODE ELECTROLYTIC CELLS, which refers to one anode structure for mercury cathode cells for industrial electrolysis of sodium chloride, said cell constituted by a grid comprising a multiplicity of blades arranged vertically and mutually parallel to each other, coated with a specific electrocatalytic coating specific for the chlorine discharge, wherein the object of the invention is to reduce consumption at the same time.

There is also the Canadian patent number 1076994 titled MOLDED, FORM RETAINING AND ELECTROLYTE RESISTANT FILLED POLYMERIC PLASTIC ELECTROLYTIC CELL FRAME, which includes a plurality of inlets and outlets for the electrolytic process fluids and mounting means for positioned cell components, such as the electrodes and the membrane, wherein passages and headers, molded into the cells, convey water and brine feeds to the cathode and anode compartments, respectively, preferably through metering orifices, and overflows from these compartments automatically maintain desired electrolyte levels that, when used, help to minimize current leakages.

Another case is the Spanish patent number U0296350, titled IONIC EXCHANGE MEMBRANE FOR ELECTROLYTIC CELL, which refers to a unique ionic exchange membrane for electrolytic cell, comprising at least one layer of first material addressed to be used as ionic exchange membrane and at least one layer of second material addressed to reinforce the membrane, said reinforcement layer being attached to at least one face of the membrane around a peripheral surface of the sealing gasket's carrier membrane.

Aforementioned references refer to cells which structure differs from the one here in depicted, since it is different and allows independent distribution of multiple feeds at the same time, it is also possible to visually inspect flow continuity through translucent restrictive hose, as well as product discharges through one upper compartment allowing a difference in height which ensures the anodic and cathodic containers fill up and separates the turbulence area from the membrane area, spilling through the translucent annular hose acting as a sight glass and breaking the current leakage to the collector pipe.

Our improvement also refers to a reinforced structure with bulges, to keep the dividing plate's seal sides of the anode and cathode plastic frames' compartments perpendicular, and also, on the aforementioned reinforcements' grid crossings there is a pole supporting the anode and cathode meshes to keep minimal flatnees and gap between electrodes, required to achieve a lesser voltage drop in the electrolytic cell, involving greater efficiency and electric power (kWh) savings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of the membrane plastic electrolytic cell of the bipolar type, wherein there are shown most parts comprising it.

FIG. 2 is a lateral view of the cell.

FIG. 3A is a cross section view of the right side arrangement of two pressed cells.

FIG. 3B is a cross section view of the left side arrangement of two cells.

DETAILED DESCRIPTION OF THE INVENTION

The improvements to this membrane plastic electrolytic cell of the bipolar type, are based on the configuration of its structure, allowing it with independent distribution of brine feeds, by means of an activated titanium electrode and steel cathode or activated nickel cathode or other metals suitable for the process and ionic exchange membranes as well as other uses in electrodialysis processes and electro-oxidation of chemical solutions.

Since it is possible to visually inspect the flow contonuity through the two translucent restrictive hoses (5) with lesser diameter, as well as in the case of the products discharges through the two upper compartments (6) and (8), wherein compartment (8) is the one allowing a difference in height which ensures the anodic and cathodic containers (not shown) fill up and separates the turbulence area from the membrane area (not shown), spilling through the translucent annular hose (11) acting as a sight glass and breaking the current leakage to the collector pipe (12).

Our improvement refers also to a reinforced structure with a bulge, to keep the dividing integral injected plastic plate's (24) seal sides of the anode and cathode plastic frames' (1) compartments perpendicular and also, on the aforementioned reinforcements' grid crossings (not shown) there is a pole (20) supporting the anode and cathode meshes (15) to keep the next cell perpendicular and to keep the minimal gap between electrodes, required to achieve a lesser voltage drop in the electrolytic cell, involving greater current efficiency and electric power (kWh) savings.

In FIG. 1, it is shown the structure or plastic frame (1), preferably rectangular, pointing out the peripheral boundaries of the cell, wherein it is shown the bas-relief or recess (2), along the complete surface of the frame, allowing formation of the anode compartment, wherein one of the lower sides has the distribution pipe (3) integrated to the plastic frame (1) that feeds brine to the anode compartment by means of the connector (4) and the flow restrictive hose (5). The feed flow is restricted to allow for the residence time required for the electrolysis reaction to take place and a restriction of current leakage to the distributor (3), spent brine and products move upward and are blocked by upper left section (6) which is not communicated with the recessed anode compartment, allowing the discharge of products and gasses by means of four holes (7) which communicate with upper right compartment which is the gasses and liquids separation unit (8), the feed to the anode compartment could be TREATED BRINE (SODIUM CHLORIDE OR POTASSIUM CHLORIDE), among others depending on the electrolytes used, and the products discharged being CHLORINE GAS, SPENT BRINE or others depending on the electrolytes, and on the side of the cathode compartment, with same parts description as the anode, but different materials and fed with TREATED WATER and the discharges or products being CAUSTIC SODA, POTASH, HYDROGEN or others depending on the electrolytes, together with a recirculation of SODA or POTASH depending on the electrolytes, to cool the cells through the same water distributor pipe to the cathode compartment, which also spills the reacted electrolyte through the two holes (9) and has a flange type connection (10), and a translucent annular hose (11) acting as a sight glass, to discharge to the section of the collector pipe (12) integrated with the group of plastic frames (1) pressed in series, said general collector of cells is integrated to the plastic frame (1) in the upper right part, also has integral independent discharges, also has a connector for the hose (13) in the lower part of the discharge of the cell, to install a sample taking device which allows for the analysis of products before they are mixed in the general collector, in order to determine the efficiency of the reaction in the cell. Both electrodes, anode and cathode have a plurality of electrical contacts (14) welded around their diameter to the mesh (15), which covers the entire surface of the cell shown in a unique section corresponding to the activated anode electrode. The electrical contacts (16) shown come from the cathode electrode which has the same description and parts shown for the activated anode electrode, it bears mentioning that only the materials of the electrical contacts (14) and the mesh (15) are different by the inner characteristics of the reaction, the union of activated anode and activated or non-activated cathode electrodes, is performed conventionally with bolts and gaskets (not shown) that make electrical connection between them, by means of a plurality of holes (17) distributed equally along and widespread the surface of the cell beneath the mesh (15), in function of the equal number of paired electrical contacts (14) and (16). The upper support of the plastic frame (19), allows the separation and sliding of the membrane plastic electrolytic cells of the bipolar type along an isolating lower rail (not shown) of the cells module (not shown), without losing the vertical position needed to keep them grouped while the cells' pressing is performed. It bears mentioning that in the lower part of the membrane plastic electrolytic cells of the biolar type are integrated two wheels (26) allowing the sliding in a pressed module. The plastic frame (1) also has a series of holes (25) where there are little plastic pins (not shown) placed, supporting the gaskets and the membrane, allowing it to fit with other holes in the same position to join two plastic frames with respective anodes and cathodes, without affecting the seal area of the compartments.

In FIG. 2 it is shown a side view of the integrated lower distributor pipe (3) and flow restrictive hose (5), discharge hose (11) and general upper collector pipe (12).

In FIG. 3A it is shown a side cross section of the anode with two identical plastic frames (1) wherein there is an arrangement containing a conventional ionic exchange membrane (22) between frames, which covers the entire surface of the meshes (15) including the peripheral area forming the lower plastic frame of the cell to seal both sides with gaskets (21), which also integrally seal with the sections of the upper compartments of products and gasses (8). The figure also shows a detailed cross section of the holes (7) communicating aforementioned upper compartments. This figure also shows the injected plastic integral dividing plate (24) that separates the anode and cathode compartments and has an arrangement of bulges or reinforcements that, besides the resistance of the cast plastic material, being polypropylene or another high mechanic and temperature resistance thermoplastic, it is added with a plurality of distributed integral grid reinforcements. FIG. 3B shows the cross section side of the cathode with two identical plastic frames (1) and the same parts shown in FIG. 3A. The use of this device is not limited to the aforementioned applications but covers any other application that obtains aforementioned results by using the same device. 

1. A membrane electrolytic cell of the bipolar type, comprising: at least one frame indicating the peripheral boundaries of the cell and wherein it creates a recessed anode compartment along the complete surface of the frame, allowing formation of anode compartments; a distribution pipe integrated into a side of the frame for creating a feed flow, for allowing brine to flow into the recessed anode compartment by means of a connector and a flow wherein the feed flow is restricted to allow for a requisite time required for an electrolysis reaction to take place and wherein a restriction of current leakage to a distributor of the spent brine such that flow is directed toward an upper portion of the frame and is blocked by an upper left section of the frame which is not in communication with the recessed anode compartment; an upper right compartment for creating a gases and liquids separation unit that allows the discharge of reacted electrolyte products and gasses by means of holes in communication between the upper right compartment gasses and liquids separation unit and the recessed anode compartment and wherein, the reacted electrolyte product passes through outlet holes from the upper right compartment gasses and liquids separation unit to a sight glass, to discharge to a general collector of cells, wherein the general collector of cells integrated to the frame; a mesh fabric covering the surface of the cell, including a plurality of electrical contacts in contact a plurality of electrodes, anodes and cathodes; an upper support of the frame for allowing the separation and sliding of the electrolytic cells with bipolar type membrane as a group along an isolating lower rail of the cells, without losing the vertical position needed to keep the grouping while cell pressing is performed; and a lower part of the electrolytic cells are integrated with one or more wheels for allowing the sliding of the module for pressing a cell.
 2. A membrane electrolytic cell of the bipolar type, according to claim 1, comprising: bolts and gaskets that make electrical connection between the union of anode and cathode electrodes and is performed by means of a plurality of holes distributed along the surface of the cell beneath the mesh, in function of the equal number of a plurality of electrical contacts.
 3. A membrane electrolytic cell of the bipolar type, according to claim 1, that comprising: at least one frame, preferably rectangular creating the recessed cell portion, having integral independent discharges, and a connector for a discharge hose in lower portion of the recessed cell; and a sample taking device which allows for the analysis of products before they are mixed in the general collector, to determine the efficiency of the reaction in the cell.
 4. A membrane bipolar electrolytic, according to claim 1, comprising: the at least one frame having a series of holes wherein pins are placed which support gaskets and membranes, and engage other holes in the same position on a second frame to join the two frames with respective anodes and cathodes, without disrupting a seal area of compartments integrated into each frame.
 5. A membrane electrolytic cell of the bipolar type, according to claim 1, comprising: at least one frame containing an ionic exchange membrane between frames, covering the entire surface of the mesh including the peripheral area forming the lower frame of the cell to seal both sides with gaskets, which also integrally seals with the sections of the upper compartments for products and gasses.
 6. A membrane electrolytic cell of the bipolar type, according to claim 1, comprising: an injected integral dividing plate for separating the anode and cathode compartments and has an arrangement of bulges or reinforcements that is added with a plurality of distributed integral grid reinforcements.
 7. A membrane plastic electrolytic cell of the bipolar type, according to claim 6, wherein the injected integral dividing plate may be plastic, polypropylene or another high mechanic and temperature resistance thermoplastic. 